Harrowing pictures emerged today appearing to show young child victims of an alleged chlorine gas attack on a rebel-held area in Syria.

A UK-based human rights organisation reported that one child died when a warplane missile “caused suffocation” among people living in al-Shifonyyah, part of the beseiged Damascus suburb of eastern Ghouta.

A further 10 people died in airstrikes on the area last night and early this morning – taking to 24 the number of reported deaths since a UN ceasefire was announced.

The suspected chemical attack happened yesterday despite the UN Security Council passing a resolution on Saturday declaring a 30-day ceasefire across the country, to enable humanitarian aid to reach Ghouta and medical evacuations to take place. Attacks continued yesterday but at a lesser rate than before.

A child receives treatment after the suspected gas attack in Ghouta (EPA)

The pictures showed several children in hospital apparently wearing oxygen masks.

The Syrian Observatory for Human Rights said there were “no reasons yet” for the cause of the suffocation, and said the death toll of 14 from attacks yesterday was expected to rise. It estimates that 521 people have died since an aerial and missile bombardment began on February 18.

Conflict set to widen with Iran now the key Assad ally

Robert Fox, Defence Editor

Iran is backing the continued air and artillery attacks on Eastern Ghouta but Syrian president Bashar al-Assad’s other principal backers, the Russians, are supporting them with reluctance.

Despite Russia signing up to Sunday’s Security Council Resolution for an “immediate” 30-day ceasefire to open up a humanitarian corridor into the two main enclaves, neither Moscow nor anyone else appear to have lifted a finger.

The commander of the Tiger Commandos, who are leading the Syria regime ground forces, says they are not covered by the ceasefire and have no intention of complying.

Two of the rebel groups in East Ghouta, Faylaq al-Rahman and Jaish al-Islam, have said they would abide by the UN ceasefire terms.

All five of the main rebel groups there want to bring strict Sharia law to Syria.

Moscow is backing Assad up to a point, and for a limited period. It will not put troops on the ground in numbers, nor does it want to be involved in subsidising a reconstruction programme. With Iran now the key Assad ally, the international aspect of Syria’s civil war seems set to widen, and become more dangerous.

Health authorities said several people had suffered symptoms consistent with exposure to chlorine gas. Victims, ambulance drivers and others smelt chlorine after “an enormous explosion”, according to a statement from the opposition Syrian Interim Government’s Ministry of Health. It said: “At least 18 victims were treated with oxygen nebulizing sessions.”

Ghouta is last major rebel-held area near the capital Damascus. Syrian regime forces of President Assad and militias backed by Iran are seeking to drive them out.

Iranian forces claimed the suburbs held by “terrorists” were not subject to the ceasefire.

In recent weeks, the US has accused Syria of repeatedly using chlorine gas as a weapon.

Child victims: Ghouta is last major rebel-held area near the capital Damascus (EPA)

The Syrian government has consistently denied using chemical weapons in the war that will soon enter its eighth year, though the UN found last year that the Syrian government was responsible for a deadly chemical attack last April.

The Russian defence ministry, which backs the Assad government, accused rebels of preparing to use toxic agents in eastern Ghouta so they could later accuse Damascus of employing chemical weapons.

Assad’s government controls more than half of Syria, including the largest cities. Other than pockets still under rebel control, most of the rest of Syria is in the hands of U.S.-backed Kurdish-led forces that wrested territory in the north and east from the Islamic State group, including the militants’ former de facto capital, Raqqa.